The present invention is generally directed to a device that is used for the treatment of various surfaces, particularly those that exhibit any degree of curvature and, more particularly, an instrument employed for rubbing or polishing, where the device is specifically envisioned as an addition to motorized hand tools, such as polishing instruments, power drills, and so on.
Machines for working on surfaces by means of a motorized rubbing or polishing disk are quite familiar, and come in various designs. These include, for example, the so-called oscillating or rotating variety of rubbing device, in which a support for the mounting of the actual tool, i.e., the sandpaper, is set in motion by means of a motor-driven, centrally rotating hub. As a general rule, the support site for the tool is positioned in the instrument casing in a manner that allows for back-and-forth movement, but its movability is ordinarily not such as would allow the rubbing surface to be applied to surfaces that curve in a concave or convex fashion.
By the use of such familiar machines, this can only be accomplished by means of changing the position of the whole machine, since the mode of operation of the rubbing device, as well as the manner in which it engages with the surface, can only be determined by the specific way in which the human operator controls the position of this device. As a consequence of this, a constant manual guidance and watchfulness are required vis-à-vis the positioning and operation of the rubbing device. Also, with regards to the force exerted upon the surface being worked on, for which reason, in working with machines of the familiar sort, it is not only necessary that the human operator possess a high degree of experience and proficiency, in order to maintain the tool in a uniform operating mode, but also, curved surfaces in part cannot be uniformly and effectively treated at all, or at least not in a satisfactory manner.
This problem has already been thoroughly resolved by means of a device that is described in DE 44 47 162 A. In this reference, three tool mountings in the form of plates for either a rubbing or polishing mechanism, are arranged in a triangular fashion. Each mounting can be driven around a longitudinal axis in order to effectuate the desired rotation, where the tool reception points for the tool mountings are installed independently of one another within the housing—and in such a way as to be movable on a mounting—for the universal turning motion of the rotation axis within the limits of a pre-determined sphere of motion, designated as “alpha.”
Each of the mountings possesses an exterior surface with an outer contour that is similar to a ball segment, which is movably received in a reception point in the housing with an inner contour that is comparable to ball segment. A driving mechanism of the machine possesses a movable ball-joint junction point, over which this drive mechanism is connected, or can be connected, with the respective tool mountings, in order to drive it into rotation in each possible positions of motion. The individual tool mountings, as well as the plates, can be decreased for exchange at the ball-joint junction point. There still remains, however, the prevalent problem of rotating tool receptions in the case of rubbing/polishing operations in general, namely that working into corners is not possible.
It is certainly true that oscillating, pendulum-type rubbing devices—possessing plates especially designed for working into corners—are also known; however, in this case, we have to do again with special appliances that have their own drive mechanism, which on the one hand are intended only for working in corners, and, thus, for example, comparatively expensive for a do-it-yourselfer in relation to the sphere of employment, and on the other hand, they are not particularly suitable for curved surfaces.